JP2842722B2 - Construction method of multi-way tunnel body - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the construction of a multi-path tunnel body which is suitable for use in a so-called multi-path tunnel body having two or more tunnel inner spaces, particularly when the tunnel is constructed by an open-cutting method. About the method.

[0002]

2. Description of the Related Art The above-mentioned open-cutting method is a method of excavating underground below the ground surface, constructing a tunnel structure in the inside of the underground excavation, and then burying the tunnel structure to form a tunnel.

[0003]

There is no suitable method for constructing a so-called double-path tunnel having two or more tunnels in a safe, easy and short time by using this excavation method. is the current situation.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances. According to a first aspect of the present invention, there is provided a base plate having a substantially T-shaped left-right symmetric base plate comprising a wall plate and a top plate. And the center of gravity is set on the vertical line passing through the ground contact surface with the ground, and the side slab is bridged between the side end surface of the top slab and the ground. Assembling one substantially arch-shaped ring having the inner space of the tunnel on both sides of the base plate as one cycle by connecting to the plate is regarded as one cycle, and this cycle is repeated to sequentially connect the rings in the tunnel construction direction. Features.

According to a second aspect of the present invention, the base plate and the side plate are joined and connected to each other while being relatively displaced in the tunnel construction direction.

[0006]

According to the method for constructing a multi-way tunnel body of the present invention,
Looking at one ring, the base plate is symmetrical and balanced, and the side plate is also balanced because its center of gravity is set on a vertical line passing through the ground contact surface with the ground. All loads reach the ground without bearing each other. In addition, one ring has a three-point support structure in which a triangle is formed by a standing point A on the ground of the base plate, a joint point B between the base plate and the side plate, and a standing point C on the ground of the side plate. Is a complex. Further, the force of the base plate in the rotation direction of the joint point B about the standing point A and the force of the side plate in the rotation direction of the joint point B of the side plate cancel each other.

[0007] Therefore, the structure is extremely balanced, and the stress applied to the base plate and the side plate is only the own load and the earth pressure, so that a structure having a very large proof stress can be obtained. In addition, since the base plate and the side plate are balanced in the installed state, the connection work between the two can be performed safely and easily, and the construction period can be shortened.

When the base plate and the side plate are joined and connected to each other while being relatively displaced in the tunnel construction direction, the load of the side plate is received by the existing ring. The side plate can be safely installed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the method of the present invention will be described below with reference to the drawings. FIG. 1 is a front view of a tunnel body T under construction according to the embodiment, and FIG. 2 is a top view of the same.

In FIG. 1, G is a horizontal ground on the inner bottom surface formed by excavating underground below the ground surface. First, a center and right and left foundations extending along the tunnel construction direction are formed on the ground G. 1 and 2 are formed by casting concrete, and grooves 1a and 2a extending along the tunnel construction direction are formed on each of the foundations 1 and 2. The groove 1a of the central foundation 1 has a rectangular cross-section, and the grooves 2a of the left and right foundations 2 are formed with a bevel so that the inner surfaces on the outer sides thereof are widened upward. Next, the mortar 3 is buried at the bottom of each of the grooves 1a and 2a with the horizontal upper surface at the same level.

Next, a symmetrical base plate 4 having a substantially T-shape in a front view is erected on the center base 1. The base plate 4 is composed of a concrete wall plate 5 and a top plate 6. First, one wall plate 5 stands upright with respect to the ground G. This wall slab 5
It has a rectangular cross section and an umbrella-shaped bulging portion 5a at the upper end, a concave portion 5b is formed on the upper surface of the bulging portion 5a, and a through hole 5c through which a person can pass is formed below. .

In order to lay the wall slab 5 on the foundation 1, the lower end thereof is fitted into the center thereof along the groove 1a of the foundation 1, and the reaction bolt 7 previously screwed into the lower end from the left and right is removed. And pressed against the inner surface of the groove 1a,
Further, a stay 8 is provided between the portion immediately below the bulging portion 5a and the left and right foundations 2. The stay 8 has a variable length via a turnbuckle 8a. The stay 8 is adjusted to the same length on the left and right sides, and the wall slab 5 stands upright with respect to the ground G. The base plate 5 is symmetrical, and the wall plate 5 is erected vertically on the horizontal ground G and the top plate 6 is in a horizontal state. However, the posture is actually held by the stay 8.

In the same manner as described above, another wall slab 5 is erected, and both are connected in accordance with the existing wall slab 5. This connection is performed by bolting joint fittings provided on the joint surface.

Next, one top plate 6 is placed on the bulging portion 5a of the two wall plates 5 standing upright. The top plate 6 is a left-right symmetric rectangular shape having a concave portion 6a formed on the lower surface to fit into the bulging portion 5a, and has the same width as the wall plate 5. The top slab 6 is placed at the center of the bulging portion 5a of the two wall slabs 5, that is, with the width thereof shifted by に in the tunnel construction direction with respect to the first erected wall slab 5. Then, the top plate 6 is fixed to the bulging portion 5a. This fixing is performed by screwing a bolt that has passed through the top plate 6 from a recess 6b formed on the top surface of the top plate 6 into an insert fitting (not shown) that has been embedded in the bulging portion 5a in advance.

As described above, the top plate 6 is placed on the two wall plates 5.
Are placed and fixed to integrate them into a state in which the base plate 4 stands on the ground G.

Thereafter, as shown in FIG. 2, the half width of the top plate 6 is placed on the bulging portion 5a of the wall plate 5 which projects toward the near side of the top plate 6 in the tunnel construction direction. The top plate 6A (end top plate) is placed and similarly fixed to the bulging portion 5a, joined to the top plate 6 and connected, and the ends are aligned. The connection between the top plates 6 and 6A is performed by bolting joint fittings embedded in the joint surface.

Next, the side plates 9 are respectively bridged between the left and right side end surfaces of the first top plate 6 and the end top plate 6A and the grooves 2a of the left and right foundations 2, and these side plates 9 Is connected to the top plate 6, 6A.

The side plate 9 is in the shape of an arc plate, has the same width as the wall plate 5 and the top plate 6, and the inside of the leg 9a is formed in a vertical plane.

In order to bridge the side plate 9 between the top plates 6 and 6A and the foundation 2, the legs 9a are arranged along the groove 2a of the foundation 2 with the convex side facing outward. At the same time, the reaction force bolt 7 screwed into the lower end thereof from the left and right is rotated in the pulling direction and pressed against the inner surface of the groove 2a, so that the joining surface on the top portion is joined to the top plates 6, 6A. Fit to face. In this state, the center of gravity W of the side plate 9 is set on the vertical line L passing through the width t of the ground contact surface 9b of the leg 9a with respect to the foundation 2. As a result, the side plate 9 stands on the base 2 and is in a balanced state without tilting to the left or right.

Thereafter, the left and right side plates 9 are connected to the top plates 6, 6A. This connection is performed by bolting joint fittings embedded in the joint surfaces of each other.

As described above, the base plate 4 composed of the wall plate 5 and the top plate 6, the end top plate 6A, and the left and right side plates 9 form one roughly having a tunnel inner space T1 on both sides of the base plate 4. The arch-shaped ring 10 is assembled. Then, in this state, the PC wire 11 is passed through a PC hole (not shown) formed in the top of the top plates 6 and 6A and the left and right side plates 9 so as to be continuous in the left-right direction in advance. At the top of
Introduce prestress in the left-right direction.

Next, the third base plate 4 is erected next to the existing second base plate 4 and connected together, and the swelling portion 5a of the wall plate 5 in these base plates 4 is formed. A new top plate 6 is placed over the slab, and these are fixed to the respective bulging portions 5a. Thereafter, the new left and right side walls 9 are connected to the first and second side walls 9A in the same manner as described above except for the end top plate 6A. The second top plate 6 is bridged between both side surfaces of the second top plate 6 and the left and right foundations 2, and these side plates 9 are joined and connected to the both top plates 6 and the existing left and right side plates 9, respectively. As a result, a substantially arch-shaped ring 10 similar to the above is assembled by the base plate 4, the top plate 6, and the left and right side plates 9, and this ring 10 is attached to the existing ring 10
It will be connected to.

As described above, the base plate 4 is replaced with the existing base plate 4.
And the top plate 6 is placed over the bulging portion 5a of the wall plate 5 of the base plate 4 and fixed to each bulging portion 5a. Between the both sides of the two existing top plates 6 and the left and right foundations 2, and these side plates 9 are attached to both the top plates 6 and the existing ring 10.
The steps of joining and connecting to each of the left and right side plates 9 to form one ring 10 and joining and connecting to the existing ring 10 are repeated, and the rings 10 are sequentially connected in the tunnel construction direction. In FIG. 2, (1) and (2)
(3) and (4) to show the order of assembly.

The transfer of the wall slab 5, the top slab 6, and the side slab 9 and the posture control are performed by hanging the crane 13 with a wire 14.

When the assembly and connection of the ring 10 have been completed in a predetermined section, the end portion of the base plate 4 projects half the width of the left and right side plates 9. Install the half-width end plate of plate 9.

As described above, a plurality of rings 10 are connected to form a tunnel wall T having two tunnel inner spaces T1.
Is completed on the ground G, the grooves 1a of the foundations 1 and 2
After solidifying 2a with mortar and burying it in the mortar, the outside of the tunnel body T is backfilled with earth and sand, and paving is performed on the ground G in the inner space T1 of the tunnel to finally obtain a tunnel. When backfilling the earth and sand, particularly in the initial stage, if the earth pressure of the earth and sand acts on the lower ends of the left and right side slabs 9 and the upper end is likely to be opened right and left, the reinforcement foundations are previously extended over the foundations 1 and 2. (Indicated by reference numeral 12 in FIG. 1) or when the foundations 1 and 2 are to be driven, the piles should be driven simultaneously.

According to the tunnel construction method of the above embodiment, when one ring 10 is viewed, the base plate 4 is symmetrical and balanced, and the side plate 9 also has its center of gravity W Since they are set on the vertical line L passing through the width t of the ground contact surface 9b of 9a, they are also in a balanced state, and their loads do not receive each other and all reach the ground G. As shown in FIG. 3, one ring 10 has an upright point A with respect to the ground G of the base plate 4, a joining point B between the top plate 6 and the side plate 9, and a vertical point A with respect to the ground G of the side plate 9. This is a composite of a three-point support structure in which a triangle is formed by setting points C. Further, the force of the base plate 4 in the direction of rotation of the joint point B about the standing point A (arrow A) and the force of the side plate 9 in the direction of rotation of the joint point B (arrow C) are mutually different. Will offset each other. In addition,
The arrow P in FIG. 3 is the direction of the prestressing compression force introduced at the top of the ring 10.

Therefore, the structure is extremely balanced, and the stress applied to the base plate 4 and the side plate 9 is only the own load and the earth pressure, so that a structure having a very large proof stress can be obtained. In addition, since the base plate 4 and the side plate 9 are balanced in the installed state, the work of connecting the two can be performed safely and easily.
Thus, the construction period can be shortened.

Further, since the base plate 4 and the side plate 9 are joined while being shifted by 1/2 of the width thereof in the tunnel construction direction, when assembling the second and subsequent rings 10, the side plate 9 is attached to the existing top. At the time of joining to the plate 6, even if a slight impact is given, the existing side plate 9 on the opposite side is received through the existing top plate 6, so that the installation of the side plate 9 can be performed more safely. It can be carried out. In FIG. 2, for example, when the side plate 9 of (17) is installed, the side plate 9 of (14) receives the impact via the top plate 6 of (12).

The wall plate 5 of the base plate 4 needs to be supported by the stays 8 for the first two, but thereafter, the wall plate 5 is connected to the base plate 4 of the existing ring. Since no support is required and the side plate 9 is not particularly required to be supported, no trouble is required for installation, and the construction period can be shortened.

The above embodiment is a method of constructing a tunnel having two tunnel inner spaces T1 on both sides using one master 4 as a base.
Are arranged in the left-right direction, the top plates 6 are connected to each other, the left and right side plates 9 are joined and connected to the side end surfaces of the top plates 6 of the base plates 4 on both sides, and there are three or more tunnel inner spaces T1. It is also possible to build a tunnel.

[0032]

As described above, according to the method for constructing a multi-way tunnel body of the present invention, since the base plate and the side plate are balanced in the installed state, the two can be connected safely and easily. Work can be carried out, thus shortening the construction period. The tunnel body is extremely well-balanced as a structural body. Therefore, there is an effect that a structure having a very large proof stress can be obtained.

[Brief description of the drawings]

FIG. 1 is a front view of a tunnel body being constructed according to an embodiment of the present invention.

FIG. 2 is a plan view of the same.

FIG. 3 is a front view schematically illustrating a ring.

[Explanation of symbols]

 4 Base plate 5 Wall plate 6 Top plate 9 Side plate 9b Tread surface 10 Ring G Ground L Vertical line T Tunnel T1 Tunnel space W Center of gravity

Claims (2)

(57) [Claims] 1. A symmetrical base plate having a substantially T-shape in front view, comprising a wall slab and a top slab, is erected on the ground, and its own center of gravity is provided between the side end surface of the top slab and the ground in the base slab. Is set on a vertical line passing through the ground contact surface with respect to the ground, and a side plate is laid over the base plate. By connecting the side plate to the top plate, one substantially arch-shaped ring having a tunnel inner space on both sides of the base plate is provided. Is a cycle, and the cycle is repeated to sequentially connect the rings in the tunnel construction direction. 2. The method for constructing a multi-way tunnel body according to claim 1, wherein the base plate and the side plate are joined and connected to each other while being relatively displaced in a tunnel construction direction. .